I think most of the important stuff on the Internet has been built. There will be continued innovation, for sure, but the great problems of the Internet have essentially been solved.

An asteroid or a supervolcano could certainly destroy us, but we also face risks the dinosaurs never saw: An engineered virus, nuclear war, inadvertent creation of a micro black hole, or some as-yet-unknown technology could spell the end of us.

If you think back to the beginning of cell phones, laptops or really any new technology, it's always expensive.

Many things are improbable, only a few are impossible.

What most people know but don't realize they know is that the world is almost entirely solar-powered already. If the sun wasn't there, we'd be a frozen ice ball at three degrees Kelvin, and the sun powers the entire system of precipitation. The whole ecosystem is solar-powered.

It is a mistake to hire huge numbers of people to get a complicated job done. Numbers will never compensate for talent in getting the right answer (two people who don't know something are no better than one), will tend to slow down progress, and will make the task incredibly expensive.

If you had to buy a new plane every time you flew somewhere, it would be incredibly expensive.